A Modeling Method for Grid-Connected Permanent Magnet Synchronous Wind Turbines

Abstract

This invention relates to the field of permanent magnet wind turbine fault diagnosis technology, and in particular to a modeling method, apparatus, equipment, and computer storage medium for grid-connected permanent magnet synchronous wind turbines. The invention establishes an Rmxprt model of the generator based on actual parameters, generates a Maxwell 3D model of the generator, establishes a three-dimensional model of the rotor magnets, and calculates the generator's moment of inertia and damping coefficient. By modifying the coercivity of the magnetic poles at specified locations, it simulates the occurrence of irreversible demagnetization faults. The generator is run under no-load conditions to calculate the generator's d-axis and q-axis inductances, and the permanent magnet flux linkage parameters. Based on these parameters, a mathematical model of the generator is established in Simulink, and a grid-connected model of the generator is also established. This invention fully considers the impact of generator demagnetization faults on motor parameter changes when a control unit is included, balancing model accuracy and computational efficiency, and improving the efficiency of generator demagnetization fault simulation.

Description

Technical Field

[0001] This invention relates to the field of fault diagnosis technology for permanent magnet wind turbines, and in particular to a modeling method, apparatus, equipment, and computer storage medium for grid-connected permanent magnet synchronous wind turbines. Background Technology

[0002] Wind power generation technology has developed rapidly in recent years, with its installed capacity steadily increasing year by year. Permanent magnet wind turbines are widely used in wind farms due to their high power density, lack of rotor excitation, reliable operation, and high efficiency. However, permanent magnets inevitably demagnetize due to the effects of high temperatures, vibrations, aging of the permanent magnet material coating, poor heat dissipation, and other electrical and mechanical faults. Once the permanent magnets of a permanent magnet wind turbine demagnetize, it will affect the generator's output power, and in severe cases, lead to generator shutdown and significant economic losses. Therefore, the detection and diagnosis of demagnetization faults in permanent magnet wind turbines is a crucial technical issue and is of great significance for ensuring the safe operation of wind power generation systems.

[0003] Currently, the main research focus on demagnetization faults in wind turbines is on the electric motor itself. There is limited work on the mechanism analysis and diagnosis of demagnetization faults in generators, and most of this work concentrates on the generator itself without fully considering the entire wind power generation system. Furthermore, since it is difficult to experimentally verify demagnetization faults in high-power generators, it is necessary to establish a simulation model of a permanent magnet wind turbine, fully considering both the generator-side and grid-side control components, to construct a complete simulation model of the wind power generation system. This model will analyze the negative effects of demagnetization faults on the wind power generation system under grid-connected operation, providing theoretical guidance for determining wind turbine operation and maintenance schemes in actual wind farms. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the fact that there is little work on the analysis and diagnosis of demagnetization fault mechanism of generators in the prior art, and most of the work is focused on the generator body without fully considering the problems of the entire wind power generation system.

[0005] To address the aforementioned technical problems, this invention provides a method for modeling grid-connected permanent magnet synchronous wind turbines, comprising:

[0006] Establish the generator Rmxprt model based on the actual generator parameters;

[0007] Based on the generator Rmxprt model, a generator Maxwell 3D model is generated, a rotor magnet 3D model is established, and the generator's moment of inertia and damping coefficient are calculated.

[0008] By modifying the coercivity of the magnetic poles at specified locations in the three-dimensional model of the rotor magnet, an irreversible demagnetization fault state is simulated.

[0009] Simulate generator no-load operation and calculate the d-axis inductance, q-axis inductance, armature resistance, and permanent magnet flux linkage parameters of the generator under normal and different demagnetization fault conditions;

[0010] A mathematical model of the generator is established in Simulink based on the moment of inertia, the damping coefficient, the d-axis inductance and q-axis inductance, the armature resistance and the permanent magnet flux linkage parameters, and a generator grid-connected model is also established.

[0011] Preferably, the actual parameters of the generator include rated parameters, generator size parameters, and permanent magnet parameters.

[0012] Preferably, establishing the three-dimensional model of the rotor magnet includes:

[0013] Select the XZ plane, draw an axial rectangular cutting surface starting from the origin, and copy it 8 times around the z-axis;

[0014] Select a permanent magnet and divide all its magnetic poles into two parts along the axial rectangular cut surface;

[0015] Select the XY plane, draw a radial rectangular cutting surface starting from the origin, cut three times along the z-axis with a preset step size, and divide the permanent magnet with a preset width into 4 pieces radially.

[0016] Preferably, the formula for simulating the irreversible demagnetization fault state by modifying the coercivity of the magnetic poles at a specified location in the 3D model of the rotor magnet is expressed as follows:

[0017] H cf =H cn (1-p)

[0018] Among them, H cf H represents the coercivity of the magnetic pole at a specified location. cn p represents the coercivity of the magnetic poles at other locations where demagnetization has not occurred, and p is the percentage of demagnetization that has occurred.

[0019] Preferably, establishing the mathematical model of the generator includes:

[0020] Based on the d-axis inductance, q-axis inductance, and resistance, establish the voltage equation:

[0021]

[0022] Where p is the percentage of demagnetization that occurs, and R s L is the armature resistance. d For the d-axis inductance, L q L0 is the q-axis inductance, and L0 is the zero-axis inductance. e Let ψ be the angular velocity of the motor. qLet ψ be the q-axis flux linkage. d For d-axis flux linkage, u d For the d-axis voltage, u q Let u0 be the q-axis voltage and u0 be the zero-axis voltage. d Let i be the d-axis current. q i is the q-axis current, and i0 is the zero-axis current;

[0023] Based on the d-axis inductance, q-axis inductance, and the flux linkage parameters of the permanent magnet, the flux linkage equation is established as follows:

[0024]

[0025] Where, ψ fault The flux linkage parameter of the permanent magnet;

[0026] Based on the d-axis inductance, q-axis inductance, and permanent magnet flux linkage parameters, the torque equation is established as follows:

[0027]

[0028] Among them, T e p is the electromagnetic torque. n It is the extreme logarithm;

[0029] Based on the moment of inertia and the damping coefficient, establish the mechanical equations:

[0030]

[0031] Where J is the moment of inertia of the generator, and B m T is the damping coefficient. L This represents the load torque.

[0032] Preferably, the generator grid-connected model includes a rectifier on the generator side and an inverter on the grid side. The rectifier adopts a fully controlled rectifier bridge composed of IGBTs, and the inverter adopts a voltage source inverter. The rectifier and the inverter are connected through a voltage stabilizing capacitor.

[0033] Preferably, the simulated generator no-load operation includes:

[0034] In the engineering tree, select the excitation option to add a current source excitation to the three-phase winding, and set the current value to 0 to simulate the generator's no-load operation.

[0035] The present invention also provides a modeling device for grid-connected permanent magnet synchronous wind turbines, comprising:

[0036] The Rmxprt model building module is used to build the generator Rmxprt model based on the actual parameters of the generator.

[0037] The 3D model building module is used to generate a Maxwell 3D model of the generator based on the generator Rmxprt model, establish a 3D model of the rotor magnet, and calculate the generator's moment of inertia and damping coefficient.

[0038] The demagnetization fault simulation module is used to simulate an irreversible demagnetization fault state by modifying the coercivity of the magnetic poles at a specified position in the three-dimensional model of the rotor magnet.

[0039] The parameter extraction module is used to simulate the no-load operation of the generator and calculate the d-axis inductance, q-axis inductance, armature resistance and permanent magnet flux linkage parameters of the generator under normal and different demagnetization fault conditions.

[0040] The generator model building module is used to build a mathematical model of the generator in Simulink based on the moment of inertia, the damping coefficient, the d-axis inductance and q-axis inductance, the armature resistance and the permanent magnet flux linkage parameters, and to build a generator grid-connected model.

[0041] This invention also provides a grid-connected permanent magnet synchronous wind turbine modeling device, comprising:

[0042] Memory, used to store computer programs;

[0043] A processor is used to implement the steps of the above-described modeling method for a grid-connected permanent magnet synchronous wind turbine when executing the computer program.

[0044] The present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described modeling method for a grid-connected permanent magnet synchronous wind turbine.

[0045] The technical solution of the present invention has the following advantages compared with the prior art:

[0046] The grid-connected permanent magnet synchronous wind turbine modeling method described in this invention uses Ansys Maxwell for finite element method (FEM) calculation to solve for generator parameters. By establishing a 3D model of the generator and setting a permanent magnet demagnetization fault at a specified location, parameters such as the generator's moment of inertia, damping coefficient, permanent magnet flux linkage, d-axis and q-axis inductance, and armature resistance under the fault condition are obtained. A set of generator parameters under the demagnetization fault is constructed, providing a foundation for the next step of establishing a mathematical model of the generator and a grid-connected wind power system. Numerical calculations based on the generator mathematical model are performed using Matlab Simulink. Using the generator parameters obtained in the previous step, a mathematical model of the generator under the demagnetization fault is constructed, fully considering the generator-side and grid-side models, to establish a complete wind power grid-connected system. The negative effects of the demagnetization fault on the wind power generation system under grid-connected operation are analyzed, providing theoretical guidance for determining the wind turbine operation and maintenance scheme for actual wind farms. Attached Figure Description

[0047] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein:

[0048] Figure 1 A flowchart illustrating the implementation of a grid-connected permanent magnet synchronous wind turbine modeling method provided by this invention;

[0049] Figure 2 This is a diagram showing the relationship between the finite element simulation based on Ansys Maxwell and the mathematical model of the generator based on Matlab Simulink.

[0050] Figure 3 This is a schematic diagram of the generator Rmxprt model;

[0051] Figure 4 This is a schematic diagram for calculating the generator's moment of inertia and damping coefficient;

[0052] Figure 5 This is a schematic diagram of the modeling and segmentation of the permanent magnet steel in the 3D model of the generator;

[0053] Figure 6 It is a schematic diagram of the three-dimensional model of the magnets of each magnetic pole of the generator;

[0054] Figure 7 This is a schematic diagram of the permanent magnet flux linkage under normal conditions, obtained through finite element simulation.

[0055] Figure 8 This is a schematic diagram of the permanent magnet flux linkage under a 20% demagnetization state obtained through finite element simulation.

[0056] Figure 9 This is a schematic diagram of the permanent magnet flux linkage under a 40% demagnetization state obtained through finite element simulation.

[0057] Figure 10 These are schematic diagrams of the d-axis and q-axis inductance obtained through finite element simulation.

[0058] Figure 11 This is a schematic diagram of a grid-connected permanent magnet wind turbine. Detailed Implementation

[0059] The core of this invention is to provide a method, device, equipment, and computer storage medium for modeling grid-connected permanent magnet synchronous wind turbines. It effectively and fully considers the impact of generator demagnetization faults on changes in motor parameters when a control unit is included, balances the accuracy and computational efficiency of the model, improves the efficiency of generator demagnetization fault simulation, and provides theoretical guidance for determining wind turbine operation and maintenance schemes in actual wind farms.

[0060] To enable those skilled in the art to better understand the present invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0061] Please refer to Figure 1 and Figure 2 , Figure 1 The flowchart illustrates the implementation of a modeling method for grid-connected permanent magnet synchronous wind turbines provided by this invention. Figure 2 This diagram illustrates the relationship between the Ansys Maxwell-based finite element simulation and the Matlab Simulink-based mathematical model of the generator in the modeling method for grid-connected permanent magnet wind turbines of this invention. The specific operation steps are as follows:

[0062] S101: Establish the generator Rmxprt model based on the actual generator parameters;

[0063] S102: Generate a Maxwell 3D model of the generator based on the generator Rmxprt model, establish a three-dimensional model of the rotor magnet, and calculate the generator's moment of inertia and damping coefficient.

[0064] S103: By modifying the coercivity of the magnetic poles at specified locations in the three-dimensional model of the rotor magnet, an irreversible demagnetization fault state is simulated.

[0065] S104: Simulate generator no-load operation and calculate the d-axis inductance, q-axis inductance, armature resistance, and permanent magnet flux linkage parameters of the generator under normal and different demagnetization fault conditions;

[0066] S105: Based on the moment of inertia, the damping coefficient, the d-axis inductance and q-axis inductance, the armature resistance and the permanent magnet flux linkage parameters, establish a mathematical model of the generator in Simulink, and establish a grid-connected model of the generator.

[0067] The stator flux linkage of a permanent magnet wind turbine is generated jointly by the stator three-phase current and the rotor permanent magnets. When the generator is running under no-load, the flux linkage generated in the stator windings is called the permanent magnet flux linkage. If a demagnetization fault occurs in the permanent magnets, the permanent magnet flux linkage will decrease, affecting the generator's operating performance. Therefore, this invention establishes a finite element 3D model of a permanent magnet wind turbine to simulate demagnetization faults of different degrees and types, obtaining parameters such as the permanent magnet flux linkage under different demagnetization faults. This data is then used to further construct a mathematical model of the generator to simulate its performance changes under grid-connected operation.

[0068] Based on the above embodiments, this embodiment takes a 4-pole permanent magnet generator with a rated power of 25kW as an example to explain step S101 in detail:

[0069] A generator Rmxprt model is established based on actual parameters. These parameters include rated parameters, generator size parameters, and permanent magnet parameters. The rated parameters are shown in Table 1, the structural parameters in Table 2, and the permanent magnet parameters in Table 3. The generator Rmxprt model is then established based on these parameters. Figure 3 As shown.

[0070] Table 1 Generator Rated Parameters

[0071]

[0072] Table 2 Generator Structural Parameters

[0073]

[0074] Table 3 Permanent Magnet Parameters

[0075]

[0076] Based on the above embodiments, this embodiment will provide a detailed description of step S102:

[0077] Since a single magnetic pole of an actual electric motor is composed of multiple magnets, while the magnetic pole of the 3D generator model is composed of a single piece of magnet, it needs to be segmented to ensure consistency with the actual motor's magnetic pole structure. The specific steps are as follows:

[0078] Select the XZ plane, draw an axial rectangular cutting surface starting from the origin, and copy it 8 times around the z-axis;

[0079] Select a permanent magnet and divide all its magnetic poles into two parts along the axial rectangular cut surface;

[0080] Select the XY plane, draw a radial rectangular cutting surface starting from the origin of the coordinate system, cut three times along the z-axis with a preset step size (15mm), and divide the permanent magnet with a preset width (60) into 4 pieces radially.

[0081] Through the above steps, each magnetic pole is divided into 8 pieces of magnet, which is consistent with the magnetic pole structure of an actual generator.

[0082] Under "motion" in the engineering tree, check "Consider mechanical transient processes" and use "calculate" to calculate the motor's moment of inertia and damping coefficient. Figure 4 As shown, the moment of inertia of the generator in this embodiment is 0.0596531 kg·m. 2The damping coefficient is 0.00328122 Ns / m.

[0083] Based on the above embodiments, this embodiment provides a detailed description of step S103:

[0084] Demagnetization faults in permanent magnet wind turbines include uniform demagnetization and non-uniform demagnetization. Uniform demagnetization refers to all magnetic poles of the permanent magnet wind turbine experiencing a certain degree of demagnetization, while non-uniform demagnetization refers to the demagnetization of some magnetic poles or parts of the magnets in a particular pole. The remanence of a permanent magnet refers to the magnetic field strength exhibited by the permanent magnet when the magnets are removed, while coercivity refers to the magnitude of the applied external reverse magnetic field strength required to make the magnetism exhibited by the permanent magnet zero. If we consider the BH curve of a permanent magnet to be approximately linear, and assuming constant permeability, modifying the coercivity of the permanent magnet is equivalent to modifying its remanence, simulating an irreversible demagnetization fault.

[0085] In step S102, each magnetic pole is divided into 8 magnets. Therefore, the occurrence of uniform demagnetization faults can be simulated by modifying the coercivity of all magnet materials, or the occurrence of different non-uniform demagnetization faults can be simulated by modifying the coercivity of the magnets at specified locations. The degree of demagnetization of the permanent magnet is represented by p. The formula for calculating the coercivity of the magnets under demagnetization faults is as follows:

[0086] H cf =H cn (1-p)

[0087] In the formula, H cf H represents the coercivity of a permanent magnet that has demagnetized, p represents the percentage of demagnetization, and H represents the coercivity of the magnet. cn This refers to the coercivity of the magnetic poles at other locations where demagnetization faults have not occurred.

[0088] In this embodiment, taking normal working conditions, 20% uniform demagnetization working conditions, and 40% uniform demagnetization working conditions as examples, the coercivity under different working conditions is calculated as shown in Table 4.

[0089] Table 4. Coercivity of Permanent Magnets under Different Operating Conditions

[0090] Operating conditions <![CDATA[H cf (A / m)]]> P(％) normal -921373 0 20% demagnetization -737098.4 20 40% demagnetization -552823.8 40

[0091] Based on the above embodiments, this embodiment provides a detailed description of step S104:

[0092] Since the stator flux linkage of a permanent magnet wind turbine is generated jointly by the three-phase stator current and the rotor permanent magnets, when the generator is running under no-load, the current flowing through the stator windings is zero. At this time, the flux linkage generated in the stator windings is caused by the permanent magnets and is called permanent magnet flux linkage. When a demagnetization fault occurs, the permanent magnet flux linkage will decrease, and the degree of decrease will be greater as the severity of the demagnetization fault increases. Accurately calculating the size of the permanent magnet flux linkage under different demagnetization conditions is crucial for subsequently establishing a mathematical model of the generator.

[0093] The specific steps to obtain the d-axis and q-axis inductance of the generator and the permanent magnet flux linkage parameters are as follows: In the engineering tree, select the excitation option, add current source excitation to the three-phase windings of Phase A, Phase B, and Phase C, and set the current value to 0 to simulate the generator's no-load operation. Set the simulation step size to 0.0002s and the simulation time to 2s. After the simulation, view the d-axis and q-axis inductance and the permanent magnet flux linkage parameters in the result. The flux linkage parameters under normal operating conditions are as follows: Figure 7 As shown, the flux linkage parameters under a 20% uniform demagnetization condition are as follows: Figure 8 As shown, the flux linkage parameters under a 40% uniform demagnetization fault are as follows: Figure 9 As shown. The d-axis inductance and q-axis inductance parameters are as follows. Figure 10 As shown.

[0094] All parameters obtained under no-load operation are shown in Table 5.

[0095] Table 5 Generator parameters under different operating conditions

[0096] Operating conditions d-axis inductance (mH) q-axis inductance (mH) Resistance (Ω) Permanent magnet flux linkage (wb) normal 4.166 4.145 0.299 1.002 20% demagnetization 4.166 4.145 0.299 0.814 40% demagnetization 4.166 4.145 0.299 0.628

[0097] Based on the above embodiments, this embodiment will provide a detailed description of step S105:

[0098] The parameters obtained in steps S102-S104 are shown in Table 6. Based on the parameters shown in Table 6, a mathematical model of the generator is established.

[0099] Table 6 Generator Parameters

[0100]

[0101] Based on the d-axis inductance, q-axis inductance, and armature resistance, establish the voltage equation:

[0102]

[0103] Where p is the percentage of demagnetization that occurs, and R s L is the armature resistance. d For the d-axis inductance, L q L0 is the q-axis inductance, and L0 is the zero-axis inductance. eLet ψ be the angular velocity of the motor. q Let ψ be the q-axis flux linkage. d For d-axis flux linkage, u d For the d-axis voltage, u q Let u0 be the q-axis voltage and u0 be the zero-axis voltage. d Let i be the d-axis current. q i is the q-axis current, and i0 is the zero-axis current.

[0104] Based on the d-axis inductance, q-axis inductance, and the flux linkage parameters of the permanent magnet, the flux linkage equation is established as follows:

[0105]

[0106] Where, ψ fault The flux linkage parameter of the permanent magnet;

[0107] Based on the d-axis inductance, q-axis inductance, and permanent magnet flux linkage parameters, the torque equation is established as follows:

[0108]

[0109] Among them, T e p is the electromagnetic torque. n It is the extreme logarithm;

[0110] Based on the moment of inertia and the damping coefficient, establish the mechanical equations:

[0111]

[0112] Where J is the moment of inertia of the generator, and B m T is the damping coefficient. L This represents the load torque.

[0113] Secondly, a grid-connected model of the wind power system is established, including the rectifier on the generator side and the inverter on the grid side. The rectifier adopts a fully controlled rectifier bridge composed of IGBTs, and the inverter adopts a voltage source inverter. The rectifier and inverter are connected through a voltage stabilizing capacitor. In this embodiment, the generator-side rectifier adopts a zero d-axis current control method with outer loop speed and inner loop current to stabilize the generator speed while maintaining maximum active power output. The grid side adopts a grid voltage-oriented vector control strategy with outer loop voltage and inner loop current to stabilize the DC-side capacitor voltage and simultaneously achieve the purpose of controlling active and reactive power output, as detailed below. Figure 11 As shown.

[0114] Using the models established in step S105 under normal and different demagnetization conditions, the changes in generator-side and grid-side parameters under demagnetization conditions were simulated. Simultaneously, to observe the transient process after a demagnetization fault occurs, the generator flux linkage parameters were set to be time-varying in the Simulink simulation. At 2 seconds, the simulation was paused, and the generator flux linkage parameters were adjusted to a 20% demagnetization fault. At 4 seconds, the generator flux linkage parameters were adjusted to a 40% demagnetization fault. The changes in generator-side current, current, speed, DC-side capacitor voltage, grid-side voltage and current, and output power were observed. The impact of different demagnetization faults on the permanent magnet wind turbine and the entire wind power system was summarized.

[0115] The above method can fully consider the impact of generator demagnetization faults on motor parameter changes when a control unit is included, taking into account both model accuracy and computational efficiency, improving the efficiency of generator demagnetization fault simulation, and providing theoretical guidance for determining wind turbine operation and maintenance schemes in actual wind farms.

[0116] This invention provides a modeling device for grid-connected permanent magnet synchronous wind turbines; the specific device may include:

[0117] The Rmxprt model building module is used to build the generator Rmxprt model based on the actual parameters of the generator.

[0118] The 3D model building module is used to generate a Maxwell 3D model of the generator based on the generator Rmxprt model, establish a 3D model of the rotor magnet, and calculate the generator's moment of inertia and damping coefficient.

[0119] The demagnetization fault simulation module is used to simulate an irreversible demagnetization fault state by modifying the coercivity of the magnetic poles at a specified position in the three-dimensional model of the rotor magnet.

[0120] The parameter extraction module is used to simulate the no-load operation of the generator and calculate the d-axis inductance, q-axis inductance, armature resistance and permanent magnet flux linkage parameters of the generator under normal and different demagnetization fault conditions.

[0121] The generator model building module is used to build a mathematical model of the generator in Simulink based on the moment of inertia, the damping coefficient, the d-axis inductance and q-axis inductance, the armature resistance and the permanent magnet flux linkage parameters, and to build a generator grid-connected model.

[0122] The grid-connected permanent magnet synchronous wind turbine modeling device of this embodiment is used to implement the aforementioned grid-connected permanent magnet synchronous wind turbine modeling method. Therefore, the specific implementation of the grid-connected permanent magnet synchronous wind turbine modeling device can be found in the embodiment section of the grid-connected permanent magnet synchronous wind turbine modeling method above. For example, the Rmxprt model building module, the three-dimensional model building module, the demagnetization fault simulation module, the parameter extraction module, and the generator model building module are respectively used to implement steps S101, S102, S103, S104, and S105 in the above-mentioned grid-connected permanent magnet synchronous wind turbine modeling method. Therefore, its specific implementation can be referred to the description of the corresponding embodiments, which will not be repeated here.

[0123] A specific embodiment of the present invention also provides a grid-connected permanent magnet synchronous wind turbine modeling device, comprising: a memory for storing a computer program; and a processor for executing the computer program to implement the steps of the above-described grid-connected permanent magnet synchronous wind turbine modeling method.

[0124] A specific embodiment of the present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described modeling method for a grid-connected permanent magnet synchronous wind turbine generator.

[0125] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0126] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0127] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0128] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0129] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A modeling method for grid-connected permanent magnet synchronous wind turbines, characterized in that, include: Establish the generator Rmxprt model based on the actual generator parameters; A Maxwell 3D model of the generator is generated based on the Rmxprt generator model. A three-dimensional model of the rotor magnet is established, and the moment of inertia and damping coefficient of the generator are calculated. The establishment of the three-dimensional model of the rotor magnet includes: Select the XZ plane, draw an axial rectangular cutting surface starting from the origin, and copy it 8 times around the z-axis; Select a permanent magnet and divide all its magnetic poles into two parts along the axial rectangular cut surface; Select the XY plane, draw a radial rectangular cutting surface starting from the origin of the coordinate system, cut three times along the z-axis according to the preset step size, and divide the permanent magnet with a preset width into 4 pieces radially; By modifying the coercivity of the magnetic poles at specified locations in the three-dimensional model of the rotor magnet, an irreversible demagnetization fault state is simulated, as expressed by the formula: in, The coercivity of the magnetic pole at a specified location, For the coercivity of magnetic poles in other locations where demagnetization faults have not occurred, The percentage of demagnetization that occurred; Simulate generator no-load operation and calculate the d-axis inductance, q-axis inductance, armature resistance, and permanent magnet flux linkage parameters of the generator under normal and different demagnetization fault conditions; A mathematical model of the generator is established in Simulink based on the moment of inertia, the damping coefficient, the d-axis inductance and q-axis inductance, the armature resistance and the permanent magnet flux linkage parameters, and a generator grid-connected model is also established.

2. The modeling method for grid-connected permanent magnet synchronous wind turbines according to claim 1, characterized in that, The actual parameters of the generator include rated parameters, generator size parameters, and permanent magnet parameters.

3. The modeling method for grid-connected permanent magnet synchronous wind turbines according to claim 1, characterized in that, The establishment of the generator mathematical model includes: Based on the d-axis inductance, q-axis inductance, and armature resistance, establish the voltage equation: in, This represents the percentage of demagnetization that occurred. For armature resistance, For d-axis inductance, It is the q-axis inductance. It is a zero-axis inductor. Let be the angular velocity of the motor. For q-axis flux linkage, For the d-axis flux linkage, The voltage along the d-axis. This is the q-axis voltage. Zero-axis voltage For d-axis current, For q-axis current, Zero-axis current; Based on the d-axis inductance, q-axis inductance, and the flux linkage parameters of the permanent magnet, the flux linkage equation is established as follows: in, The flux linkage parameter of the permanent magnet; Based on the d-axis inductance, q-axis inductance, and permanent magnet flux linkage parameters, the torque equation is established as follows: in, For electromagnetic torque, It is the extreme logarithm; Based on the moment of inertia and the damping coefficient, establish the mechanical equations: in, Let be the moment of inertia of the generator. The damping coefficient is... This represents the load torque.

4. The modeling method for grid-connected permanent magnet synchronous wind turbines according to claim 1, characterized in that, The generator grid-connected model includes a rectifier on the generator side and an inverter on the grid side. The rectifier adopts a fully controlled rectifier bridge composed of IGBTs, and the inverter adopts a voltage source inverter. The rectifier and the inverter are connected through a voltage stabilizing capacitor.

5. The modeling method for grid-connected permanent magnet synchronous wind turbines according to claim 1, characterized in that, The simulated generator no-load operation includes: In the engineering tree, select the excitation option to add a current source excitation to the three-phase winding, and set the current value to 0 to simulate the generator's no-load operation.

6. A modeling device for grid-connected permanent magnet synchronous wind turbines, characterized in that, include: The Rmxprt model building module is used to build the generator Rmxprt model based on the actual parameters of the generator. The 3D model building module is used to generate a Maxwell 3D model of the generator based on the generator Rmxprt model, establish a 3D model of the rotor magnet, and calculate the generator's moment of inertia and damping coefficient. Establishing the 3D model of the rotor magnet includes: Select the XZ plane, draw an axial rectangular cutting surface starting from the origin, and copy it 8 times around the z-axis; Select a permanent magnet and divide all its magnetic poles into two parts along the axial rectangular cut surface; Select the XY plane, draw a radial rectangular cutting surface starting from the origin of the coordinate system, cut three times along the z-axis according to the preset step size, and divide the permanent magnet with a preset width into 4 pieces radially; The demagnetization fault simulation module is used to simulate an irreversible demagnetization fault state by modifying the coercivity of the magnetic poles at specified locations in the three-dimensional model of the rotor magnet. The formula is expressed as: in, The coercivity of the magnetic pole at a specified location, For the coercivity of magnetic poles in other locations where demagnetization faults have not occurred, The percentage of demagnetization that occurred; The parameter extraction module is used to simulate the no-load operation of the generator and calculate the d-axis inductance, q-axis inductance, armature resistance and permanent magnet flux linkage parameters of the generator under normal and different demagnetization fault conditions. The generator model building module is used to build a mathematical model of the generator in Simulink based on the moment of inertia, the damping coefficient, the d-axis inductance and q-axis inductance, the armature resistance and the permanent magnet flux linkage parameters, and to build a generator grid-connected model.

7. A modeling device for grid-connected permanent magnet synchronous wind turbines, characterized in that, include: Memory, used to store computer programs; A processor, configured to execute the computer program to implement the steps of the modeling method for a grid-connected permanent magnet synchronous wind turbine as described in any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the modeling method for a grid-connected permanent magnet synchronous wind turbine as described in any one of claims 1 to 5.

Images